(a) Field of the Invention
According to the present invention, hereinafter the term “LED” is the abbreviation of the light-emitting diode;
The present invention relates to a LED device with shared voltage-limiting unit and individual voltage-equalizing resistance, wherein two ends of a LED set constituted by a plurality of same-polarity series LEDs are in parallel connected with a shared voltage-limiting unit, and two ends of individual LED are respectively in parallel connected with an voltage-equalizing resistance for providing an overvoltage protection to the LEDs, so when surge voltage from a power source is generated, the surge voltage can be absorbed by the shared voltage-limiting unit, so that individual LED is protected from being damaged due to instant overvoltage or overcurrent.
(b) Description of the Prior Art
Conventional LEDs usually parallel connect with the voltage-limiting units at two ends of each LED, such as the zener diode, to constitute the light-emitting unit, thereby when the end voltage of LED is abnormally increased, the abnormal voltage is absorbed by the zener diode; however, when the light-emitting units being parallel connected by the above mentioned LED and the zener diode are series connected (including series-parallel connected) in plural sets to constitute the light-emitting unit, the voltage is not able to be evenly distributed due to the different properties of the LED and the zener diode, so that when subject to abnormal high voltage, the LED loaded with higher end voltage is passed by the higher current therefore the LED is often damaged.